This invention relates to an electronic musical instrument and more particularly to an electronic musical instrument in which frequency informations corresponding to tone pitch of respective keys of a keyboard are stored in a frequency information memory device and musical tones corresponding to depressed keys are formed by reading out waveshape memories using the informations from the frequency information memory device.
In the electronic musical instrument of the type described above, since the musical tones are generated through digital processing, for example by reading out frequency information corresponding to tone pitch of respective keys from the frequency information memory, and by reading out waveshape information necessary for generating musical tones from the waveshape memory using the frequency information, it is possible to generate many tone colors (waveshape) and various musical effects and such musical instrument is characterized by enriching the represention of music.
In such a musical instrument, it has been proposed a footage change in which the pitches of the generated musical tones are shifted by an octave unit. The purpose of the footage change is to improve the effect of a concert and to obtain most suitable footage for the music played when the electronic musical instrument is played in a concert with other musical instruments. In order to enable to simply and readily change the register footage at the time of commencing a performance or during the performance, it is desirable to preset a footage signal.
Among musical instruments with footage change may be mentioned a copending U.S. patent application Ser. No. 678,709 filed on Apr. 20, 1976 by Teruo Hiyoshi et al and now U.S. Pat. 4,082,027 of the title "Electronic Musical Instrument." In the electronic musical instrument disclosed in this patent application, when a footage change is desired, the player manually operates a footage change knob to perform a desired footage change. To perform a footage change it is necessary to adjust the volume and color of the tone so that the player is required to manually operate the knobs for adjusting the volume and color concurrently with the adjustment of the footage change knob.
However it is troublesome and time consuming to operate various knobs.